import { execSync } from 'child_process'
import fs from 'fs' 
import { parse, stringify } from 'envfile'
    
export const AO_ENV_FILE_PATH = process.env.HOME + '/.ao/.env'

function createAoFolderIfDoesNotExist() {
  
}

// Check for an AO env file at ~/.ao/.env and returns true if it exists
export function checkAoEnvFile() {
  try {
    execSync(`[ -f "${AO_ENV_FILE_PATH}" ]`)
    return true
  } catch(err) {
    return false
  }
}

export function aoEnv(variable) {
  let envFileContents = {}
  try {
    envFileContents = fs.readFileSync(AO_ENV_FILE_PATH)
  } catch(err) {
    if(err.code === 'ENOENT') {
      console.log('The .env file does not exist, so the requested value', variable, 'is empty.')
    } else {
      console.log('Unknown error loading .env file in aoEnv, aborting.')
      return null
    }
  }
  const parsedFile = parse(envFileContents)
  
  if(!parsedFile.hasOwnProperty(variable)) {
    return null
  }
  
  // Convert ENV idiom to programmatic types
  switch(parsedFile[variable]) {
    case '1':
    case 'true':
    case 'TRUE':
    case 'yes':
    case 'YES':
      return true
    case '0':
    case 'false':
    case 'FALSE':
    case 'no':
    case 'NO':
      return false
  }
  
  return parsedFile[variable]
}

// Sets and saves the given ENV=value to the global ~/.ao/.env file
// If value is null, the env variable will be deleted
// Returns true if a change was made, false if no change was made or if it failed
export function setAoEnv(variable, value) {
  createAoFolderIfDoesNotExist()
  if(typeof variable !== 'string') {
    console.log('ENV variable name must be a string for setAoEnv')
    return false
  }
  
  // Convert types to standard ENV file idiom
  switch(value) {
    case true:
    case 'TRUE':
    case 'yes':
    case 'YES':
      value = '1'
      break
    case false:
    case 'FALSE':
    case 'no':
    case 'NO':
      value = '0'
  }
  
  let envFileContents = {}
  try {
    envFileContents = fs.readFileSync(AO_ENV_FILE_PATH)
  } catch(err) {
    if(err.code === 'ENOENT') {
      console.log('The .env file hasn\'t been created yet, creating.')
    } else {
      console.log('Unknown error loading .env file in setAoEnv, aborting. Error:', err)
      return false
    }
  }
  
  const parsedFile = parse(envFileContents)
  if(parsedFile[variable] == value) {
    console.log(variable, 'is already', value, 'so no change was made.')
    return false
  }
  
  if(value === null) {
    delete parsedFile[variable]
  } else {
    parsedFile[variable] = value
  }
  
  const stringified = stringify(parsedFile)
  fs.writeFileSync(AO_ENV_FILE_PATH, stringified)
  
  // Confirm the variable was set in the .env file correctly
  if(aoEnv(variable) != value) {
    console.log('Value was not saved correctly, sorry.')
    return false
  }
  return true
}

function setAndSaveEnvironmentVariable(variable, value, path) {
  
}